1. Field of the Invention
The present invention generally relates to Storage Area Networks (SANs). More specifically, the present invention provides techniques and mechanisms for allowing improved data transfer efficiency for hosts and targets connected to SANs.
2. Description of Related Art
Storage Area Networks (SANs) provide an effective mechanism for maintaining and managing large amounts of data. A host can obtain data from a device such as a tape device through a fibre channel fabric having a number of fibre channel switches. However, storage area networks are often limited in geographic scope. Fibre channel fabrics in different geographic areas or separate fibre channel fabrics often have limited ability to interoperate.
Protocols such as Fibre Channel over the Internet Protocol (FCIP) allow devices on different fibre channel fabrics to communicate. FCIP is one protocol that allows the creation of a wide area network (WAN) connecting hosts and tape resources. For example, two separate fibre channel fabrics may be connected through an IP network. A host device on a first fibre channel fabric can read data from a device on a second fibre channel fabric through the IP network. However, reading data over an IP network from a separate fibre channel network can often be inefficient. Round trip times for commands and data can often introduce high latency into various storage applications, such as applications involving bulk data transfers or tape backup operations. Some limited acceleration mechanisms are available for improving data transfer efficiency. However, configuration and management of existing acceleration mechanisms are involved and complicated.
Consequently, it is desirable to provide improved techniques for allowing efficient and effective transfer of data between SAN hosts and targets.